The objective of this study is to assess and compare the effects of usual diets containing lean beef vs. lean poultry on pancreatic beta-cell responses in men and women with prediabetes.

Inclusion Criteria:

1. Male or female 18 to 74 y of age, inclusive.
2. Subject has a BMI of 25.0-39.9 kg/m2, inclusive.
3. Subject has a Vein Access Scale score of 7-10.
4. Subject has prediabetes as indicated by a fasting plasma glucose of 100-125 mg/dL and/or HbA1c of 5.7%-6.4% at screening.
5. Subject is normally active and judged by the Investigator to be in general good health on the basis of medical history and screening measurements.
6. Subject is willing to consume study-related foods and follow the dietary instructions during each 4-week treatment period.
7. Subject is willing to come to the clinic for study food pick-up if needed.
8. Subject is willing to follow his/her usual physical activity pattern throughout the study period.
9. Subject agrees to avoid meat, poultry, seafood, and eggs, other than the study entrées, for the duration of the treatment periods.
10. Subject has no plans to change smoking habits during the study period.
11. Subject is willing to refrain from consumption of recreational marijuana and alcoholic beverages for 24 h prior to each clinic visit.
12. Subject is willing to refrain from vigorous physical activity for 24 h prior to each clinic visit.
13. Subject is willing to abstain from tobacco/nicotine products and caffeine use for at least 1 h prior to and during each clinic visit.
14. Subject understands the study procedures and signs forms documenting informed consent to participate in the study and authorization for release of relevant protected health information to the study Investigator and is willing to complete study procedures.

Exclusion Criteria:

1. Subject has a laboratory test result of clinical significance based on the judgment of the Principal Investigator or qualified designee.
2. Subject has fasting blood glucose ≥ 126 mg/dL and/or HbA1c ≥ 6.5% at screening and/or known type 1 or type 2 diabetes mellitus.
3. Subject has atherosclerotic cardiovascular disease including any of the following: clinical signs of atherosclerosis including peripheral arterial disease, abdominal aortic aneurysm, carotid artery disease (symptomatic [e.g., myocardial infarction, angina, transient ischemic attack, or stroke of carotid origin] or > 50% stenosis on angiography or ultrasound) or other forms of clinical atherosclerotic disease (e.g., renal artery disease).
4. Subject has history or presence of a clinically significant health condition that, in the opinion of the Investigator, could interfere with the interpretation of the study results.
5. Subject has a history of cancer in the prior 2 years, other than non-melanoma skin cancer or carcinoma in situ of the cervix.
6. Subject has uncontrolled hypertension (systolic blood pressure ≥ 160 mm Hg and/or diastolic blood pressure ≥ 100 mm Hg) at screening.
7. Subject has unstable use (defined as initiation or change in dose) of anti-hypertensive medication or thyroid hormone replacement within 4 weeks of screening (Appendix 1).
8. Subject has used alpha- or beta-adrenergic blockers and/or high-dose (> 25 mg/d) thiazide diuretics within 4 weeks of screening (Appendix 1).
9. Subject has used diabetes medications including any alpha-glucosidase inhibitor, biguanide (metformin), thiazolidinedione, dipeptidyl peptidase-4 inhibitor, meglitinide, sulfonylurea, Sodium-glucose Cotransporter-2 inhibitor, or GLP-1 receptor agonist within 4 weeks of screening (Appendix 1).
10. Subject has used systemic corticosteroids within 4 weeks of screening (Appendix 1).
11. Subject has used weight-loss drugs (including over-the-counter medications and/or supplements) or programs within 4 weeks prior to screening (Appendix 1).
12. Subject has used dietary supplements that may affect carbohydrate metabolism, including chromium picolinate, ginseng, cinnamon (as a supplement) and starch blockers within 2 weeks of screening (Appendix 1).
13. Subject has used any lipid altering drug therapy except stable use statin therapy (stable use is defined as no change in agent, dose, or regimen in the 4 weeks prior to screening).
14. Subject has had a weight change of ± 4.5 kg (10 lbs) in the previous 3 months.
15. Subject has an active infection and/or is on antibiotic therapy. Subject can be rescheduled for screening at least 7 days after completion of antibiotic therapy.
16. Subject has restrictive dietary habits (e.g., vegan, vegetarian, or very low carbohydrate diet).
17. Subject has a history of a diagnosed eating disorder (e.g., anorexia or bulimia nervosa).
18. Subject is a female who is pregnant, planning to be pregnant during the study period, lactating, or is of childbearing potential and is unwilling to commit to the use of a medically approved form of contraception throughout the study period.
19. Subject has a known allergy, sensitivity, or intolerance to any of the study foods.
20. Subject has been exposed to any non-registered drug product within 30 days of screening.
21. Subject has a current or recent history (past 12 months of screening) or strong potential for illicit drug or alcohol abuse. Alcohol abuse will be defined as >14 drinks per week (1 drink = 12 oz beer, 5 oz wine, or 1.5 oz hard liquor).
22. Subject has a condition the Investigator believes would interfere with his or her ability to provide informed consent or comply with the study protocol, or which might confound the interpretation of the study results or put the person at undue risk.